The pleasing esthetic qualities of water flowing in a sheet are well recognized and certain types of spouts for producing these sheets are known. In one type of "sheet flow spout" such as that of U.S. Pat. No. 4,334,328, a narrow slot is formed having a cross-section matching that of the desired sheet of water. A flow chamber between the water supply and the narrow slot smooths the flow of the water so that when it exits the narrow slot, it continues as a sheet for a distance. Producing a wide sheet of water with such a design, using practical rates of water flow, requires that the slot be narrow. Manufacturing a narrow slot is difficult and such a narrow slot may be difficult to clean or susceptible to clogging.
In a second type of sheet flow spout, the narrow slot is replaced by a single deflector which is impinged by a stream of water from a nozzle. The water spreads upon impact with the deflector to form the sheet. This spreading of the water as it strikes the deflector also limits the free length of the sheet before it breaks up into droplets. This is because the thinning of the expanding sheet soon exceeds the limits of surface tension of the water holding the sheet together.
This problem of the diverging sheet thinning too quickly may, to some extent, be overcome by the use of multiple jets, each of which "shepherds" a neighboring jet to prevent the excessive spreading of the water after it leaves the deflector. See e.g. U.S. Pat. No. 4,912,782.
Unfortunately, the use of multiple jets may produce a sheet of uneven thickness and, in any event, may be costly.